Can't uninstall - WSOD - commerce_stock_always_in_stock field values don't delete

Problem/Motivation

Hi,

I'm trying to uninstall the commerce_stock_local module but can't. It needs to remove "commerce_stock_always_in_stock field values", as reported on the uninstall screen, but it fails with a WSOD and error:
Error: Call to undefined method Drupal\Core\Config\Entity\ConfigEntityType::isSubclassOf() in Drupal\commerce_stock_local\Form\PrepareUninstallForm->submitForm() (line 90 of /var/www/XXX/modules/contrib/commerce_stock/modules/local_storage/src/Form/PrepareUninstallForm.php).

Stacktrace:

#0 [internal function]: Drupal\commerce_stock_local\Form\PrepareUninstallForm->submitForm()
#1 /var/www/XXX/core/lib/Drupal/Core/Form/FormSubmitter.php(129): call_user_func_array()
#2 /var/www/XXX/core/lib/Drupal/Core/Form/FormSubmitter.php(67): Drupal\Core\Form\FormSubmitter->executeSubmitHandlers()
#3 /var/www/XXX/core/lib/Drupal/Core/Form/FormBuilder.php(597): Drupal\Core\Form\FormSubmitter->doSubmitForm()
#4 /var/www/XXX/core/lib/Drupal/Core/Form/FormBuilder.php(325): Drupal\Core\Form\FormBuilder->processForm()
#5 /var/www/XXX/core/lib/Drupal/Core/Controller/FormController.php(73): Drupal\Core\Form\FormBuilder->buildForm()
#6 [internal function]: Drupal\Core\Controller\FormController->getContentResult()
#7 /var/www/XXX/core/lib/Drupal/Core/EventSubscriber/EarlyRenderingControllerWrapperSubscriber.php(123): call_user_func_array()
#8 /var/www/XXX/core/lib/Drupal/Core/Render/Renderer.php(627): Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}()
#9 /var/www/XXX/core/lib/Drupal/Core/EventSubscriber/EarlyRenderingControllerWrapperSubscriber.php(121): Drupal\Core\Render\Renderer->executeInRenderContext()
#10 /var/www/XXX/core/lib/Drupal/Core/EventSubscriber/EarlyRenderingControllerWrapperSubscriber.php(97): Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->wrapControllerExecutionInRenderContext()
#11 /var/www/XXX/vendor/symfony/http-kernel/HttpKernel.php(181): Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}()
#12 /var/www/XXX/vendor/symfony/http-kernel/HttpKernel.php(76): Symfony\Component\HttpKernel\HttpKernel->handleRaw()
#13 /var/www/XXX/core/lib/Drupal/Core/StackMiddleware/Session.php(58): Symfony\Component\HttpKernel\HttpKernel->handle()
#14 /var/www/XXX/core/lib/Drupal/Core/StackMiddleware/KernelPreHandle.php(48): Drupal\Core\StackMiddleware\Session->handle()
#15 /var/www/XXX/core/lib/Drupal/Core/StackMiddleware/ContentLength.php(28): Drupal\Core\StackMiddleware\KernelPreHandle->handle()
#16 /var/www/XXX/core/modules/page_cache/src/StackMiddleware/PageCache.php(106): Drupal\Core\StackMiddleware\ContentLength->handle()
#17 /var/www/XXX/core/modules/page_cache/src/StackMiddleware/PageCache.php(85): Drupal\page_cache\StackMiddleware\PageCache->pass()
#18 /var/www/XXX/core/lib/Drupal/Core/StackMiddleware/ReverseProxyMiddleware.php(48): Drupal\page_cache\StackMiddleware\PageCache->handle()
#19 /var/www/XXX/core/lib/Drupal/Core/StackMiddleware/NegotiationMiddleware.php(51): Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle()
#20 /var/www/XXX/core/lib/Drupal/Core/StackMiddleware/AjaxPageState.php(36): Drupal\Core\StackMiddleware\NegotiationMiddleware->handle()
#21 /var/www/XXX/core/lib/Drupal/Core/StackMiddleware/StackedHttpKernel.php(51): Drupal\Core\StackMiddleware\AjaxPageState->handle()
#22 /var/www/XXX/core/lib/Drupal/Core/DrupalKernel.php(704): Drupal\Core\StackMiddleware\StackedHttpKernel->handle()
#23 /var/www/XXX/index.php(19): Drupal\Core\DrupalKernel->handle()
#24 {main}

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes